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Cell Reports Jun 2024In contrast to most hematopoietic lineages, megakaryocytes (MKs) can derive rapidly and directly from hematopoietic stem cells (HSCs). The underlying mechanism is...
In contrast to most hematopoietic lineages, megakaryocytes (MKs) can derive rapidly and directly from hematopoietic stem cells (HSCs). The underlying mechanism is unclear, however. Here, we show that DNA damage induces MK markers in HSCs and that G2 arrest, an integral part of the DNA damage response, suffices for MK priming followed by irreversible MK differentiation in HSCs, but not in progenitors. We also show that replication stress causes DNA damage in HSCs and is at least in part due to uracil misincorporation in vitro and in vivo. Consistent with this notion, thymidine attenuated DNA damage, improved HSC maintenance, and reduced the generation of CD41 MK-committed HSCs. Replication stress and concomitant MK differentiation is therefore one of the barriers to HSC maintenance. DNA damage-induced MK priming may allow rapid generation of a lineage essential to immediate organismal survival, while also removing damaged cells from the HSC pool.
PubMed: 38935497
DOI: 10.1016/j.celrep.2024.114388 -
Genome Biology and Evolution Jun 2024De novo genes emerge from non-coding regions of genomes via succession of mutations. Among others, such mutations activate transcription and create a new open reading...
De novo genes emerge from non-coding regions of genomes via succession of mutations. Among others, such mutations activate transcription and create a new open reading frame (ORF). Although the mechanisms underlying ORF emergence are well documented, relatively little is known about the mechanisms enabling new transcription events. Yet, in many species a continuum between absent and very prominent transcription has been reported for essentially all regions of the genome. In this study we searched for de novo transcripts by using newly assembled genomes and transcriptomes of seven inbred lines of Drosophila melanogaster, originating from six European and one African population. This setup allowed us to detect sample specific de novo transcripts, and compare them to their homologous non-transcribed regions in other samples, as well as genic and intergenic control sequences. We studied the association with transposable elements and the enrichment of transcription factor motifs upstream of de novo emerged transcripts and compared them with regulatory elements. We found that de novo transcripts overlap with TEs more often than expected by chance. The emergence of new transcripts correlates with regions of high GC content and TE expression. Moreover, upstream regions of de novo transcripts are highly enriched with regulatory motifs. Such motifs are more enriched in new transcripts overlapping with TEs, particularly DNA TEs, and are more conserved upstream de novo transcripts than upstream their 'non-transcribed homologs'. Overall, our study demonstrates that TE insertion is important for transcript emergence, partly by introducing new regulatory motifs from DNA TE families.
PubMed: 38934893
DOI: 10.1093/gbe/evae134 -
Indian Journal of Public Health Oct 2023LAMP assay is widely used for detecting pathogens. We observed that the conventional and gradient polymerase chain reaction (PCR) could not detect the extracted...
Electrophoresis of Amplicons is a Better Method to Understand the Performance of Loop-mediated Isothermal Amplification Assay for Screening the Presence of Escherichia coli in Water.
LAMP assay is widely used for detecting pathogens. We observed that the conventional and gradient polymerase chain reaction (PCR) could not detect the extracted Escherichia coli DNA; real-time PCR was able to detect up to a certain limit (10-8 bacterial dilution). At the same time, the LAMP assay could detect the bacteria at a much lower concentration (10-14 dilution). The results of the LAMP assay were evaluated using agarose gel electrophoresis and DNA binding dye (PicoGreen), but only gel electrophoresis gave reliable results. Therefore, we propose using electrophoresis-based amplicon detection to overcome the limitations of dye-based detection. We believe that this amplicon detection will go a long way in the screening of potable drinking water.
Topics: Escherichia coli; Nucleic Acid Amplification Techniques; Water Microbiology; Real-Time Polymerase Chain Reaction; Humans; Electrophoresis, Agar Gel; DNA, Bacterial; Molecular Diagnostic Techniques; Drinking Water
PubMed: 38934812
DOI: 10.4103/ijph.ijph_1628_22 -
Journal of Microbiology and... Jun 2024The antimicrobial activity of the natural compounds from plant and food have well discovered since the interest on the beneficial effect of the natural compounds was...
The antimicrobial activity of the natural compounds from plant and food have well discovered since the interest on the beneficial effect of the natural compounds was risen. Quercetin, a flavonoid derived from vegetables, including onions, red leaf lettuces and cherries has been studied for diverse biological characteristics as anti-cancer and anti-microbial activities. The aim of current study is to investigate the specific antibacterial modes of action of quercetin against Quercetin decreased the cell viability and induced the severe damages (oxidative stress, DNA fragmentation) leading to cell death. ROS generation was observed during the process, which we confirmed that oxidative stress was the key action of antibacterial activity of quercetin exerting its influence potently. Based on the results of Annexin V and Caspace FITC-VAD-FMK assay, the oxidative damage in has led to the bacterial apoptosis-like death in . To sum up, the contribution of ROS generation exerts crucial impact in antibacterial activity of quercetin.
PubMed: 38934783
DOI: 10.4014/jmb.2403.03057 -
Hepatology Communications Jul 2024MASH is a common clinical disease that can lead to advanced liver conditions, but no approved pharmacotherapies are available due to an incomplete understanding of its...
BACKGROUND
MASH is a common clinical disease that can lead to advanced liver conditions, but no approved pharmacotherapies are available due to an incomplete understanding of its pathogenesis. Damaged DNA binding protein 1 (DDB1) participates in lipid metabolism. Nevertheless, the function of DDB1 in MASH is unclear.
METHODS
Clinical liver samples were obtained from patients with MASH and control individuals by liver biopsy. Hepatocyte-specific Ddb1-knockout mice and liver Hmgb1 knockdown mice were fed with a methionine-and choline-deficient diet to induce MASH.
RESULTS
We found that the expression of DDB1 in the liver was significantly decreased in MASH models. Hepatocyte-specific ablation of DDB1 markedly alleviated methionine-and choline-deficient diet-induced liver steatosis but unexpectedly exacerbated inflammation and fibrosis. Mechanistically, DDB1 deficiency attenuated hepatic steatosis by downregulating the expression of lipid synthesis and uptake genes. We identified high-mobility group box 1 as a key candidate target for DDB1-mediated liver injury. DDB1 deficiency upregulated the expression and extracellular release of high-mobility group box 1, which further increased macrophage infiltration and activated HSCs, ultimately leading to the exacerbation of liver inflammation and fibrosis.
CONCLUSIONS
These data demonstrate the independent regulation of hepatic steatosis and injury in MASH. These findings have considerable clinical implications for the development of therapeutic strategies for MASH.
Topics: Animals; Mice; Hepatocytes; Liver Cirrhosis; Mice, Knockout; DNA-Binding Proteins; Humans; HMGB1 Protein; Fatty Liver; Male; Choline Deficiency; Disease Models, Animal; Methionine; Liver; Lipid Metabolism
PubMed: 38934719
DOI: 10.1097/HC9.0000000000000474 -
MSystems Jun 2024The skin microbiome plays a pivotal role in human health by providing protective and functional benefits. Furthermore, its inherent stability and individual specificity...
The skin microbiome plays a pivotal role in human health by providing protective and functional benefits. Furthermore, its inherent stability and individual specificity present novel forensic applications. These aspects have sparked considerable research enthusiasm among scholars across various fields. However, the selection of specific 16S rRNA hypervariable regions for skin microbiome studies is not standardized and should be validated through extensive research tailored to different research objectives and targeted bacterial taxa. Notably, third-generation sequencing (TGS) technology leverages the full discriminatory power of the 16S gene and enables more detailed and accurate microbial community analyses. Here, we conducted full-length 16S sequencing of 141 skin microbiota samples from multiple human anatomical sites using the PacBio platform. Based on this data, we generated derived 16S sub-region data through an experiment. Comparisons between the 16S full-length and the derived variable region data revealed that the former can provide superior taxonomic resolution. However, even with full 16S gene sequencing, limitations arise in achieving 100% taxonomic resolution at the species level for skin samples. Additionally, the capability to resolve high-abundance bacteria (TOP30) at the genus level remains generally consistent across different 16S variable regions. Furthermore, the V1-V3 region offers a resolution comparable with that of full-length 16S sequences, in comparison to other hypervariable regions studied. In summary, while acknowledging the benefits of full-length 16S gene analysis, we propose the targeting of specific sub-regions as a practical choice for skin microbial research, especially when balancing the accuracy of taxonomic classification with limited sequencing resources, such as the availability of only short-read sequencing or insufficient DNA.IMPORTANCESkin acts as the primary barrier to human health. Considering the different microenvironments, microbial research should be conducted separately for different skin regions. Third-generation sequencing (TGS) technology can make full use of the discriminatory power of the full-length 16S gene. However, 16S sub-regions are widely used, particularly when faced with limited sequencing resources including the availability of only short-read sequencing and insufficient DNA. Comparing the 16S full-length and the derived variable region data from five different human skin sites, we confirmed the superiority of the V1-V3 region in skin microbiota analysis. We propose the targeting of specific sub-regions as a practical choice for microbial research.
PubMed: 38934545
DOI: 10.1128/msystems.00399-24 -
Microbial Biotechnology Jun 2024Bdellovibrio bacteriovorus HD100 is an obligate predatory bacterium that preys upon Gram-negative bacteria. It has been proposed to be applied as a "living antibiotic"...
Bdellovibrio bacteriovorus HD100 is an obligate predatory bacterium that preys upon Gram-negative bacteria. It has been proposed to be applied as a "living antibiotic" in several fields such as agriculture or even medicine, since it is able to prey upon bacterial pathogens. Its interesting lifestyle makes this bacterium very attractive as a microbial chassis for co-culture systems including two partners. A limitation to this goal is the scarcity of suitable synthetic biology tools for predator domestication. To fill this gap, we have firstly adapted the hierarchical assembly cloning technique Golden Standard (GS) to make it compatible with B. bacteriovorus HD100. The chromosomal integration of the Tn7 transposon's mobile element, in conjunction with the application of the GS technique, has allowed the systematic characterization of a repertoire of constitutive and inducible promoters, facilitating the control of the expression of heterologous genes in this bacterium. PJ/EliR proved to be an exceptional promoter/regulator system in B. bacteriovorus HD100 when precise regulation is essential, while the synthetic promoter P showed a constitutive high expression. These genetic tools represent a step forward in the conversion of B. bacteriovorus into an amenable strain for microbial biotechnology approaches.
Topics: Synthetic Biology; Bdellovibrio bacteriovorus; Gene Expression Regulation, Bacterial; Promoter Regions, Genetic; DNA Transposable Elements; Cloning, Molecular; Recombinant Proteins
PubMed: 38934530
DOI: 10.1111/1751-7915.14517 -
Archivio Italiano Di Urologia,... Jun 2024Single sperm cryopreservation (SSC) is a specific technique especially used in individuals with small numbers of sperm who suffered from non-obstructive azoospermia...
Pentoxifylline treatment as a safe method for selecting viable testicular spermatozoa before cryopreservation of a small numbers of spermatozoa in azoospermia individuals.
BACKGROUND
Single sperm cryopreservation (SSC) is a specific technique especially used in individuals with small numbers of sperm who suffered from non-obstructive azoospermia (NOA). Testicular specimens possess poor motility and low population of viable spermatozoa. Therefore, sperm selection methods such as applying pentoxifylline (PTX) may improve motility in these cases. The main aim of this study was to evaluate the protective effects of PTX on testicular spermatozoa before and after performing SSC.
METHODS
Thirty testicular samples were obtained from men with azoospermia. This study was conducted in two phases. Phase 1 evaluated the effect of PTX for sperm selection before SSC. Twenty testicular samples were divided to two experimental groups: SSC without (I) and with PTX treatment (II). For PTX treatment spermatozoa were incubated with PTX at 37°C for 30 min and only motile spermatozoa were selected for SSC. In phase 2, ten testicular samples were cryopreserved with SSC and warming procedure was carried out in droplet with and without PTX. Motility and viability rates, morphology by motile sperm organelle morphology examination (MSOME), DNA fragmentation by sperm chromatin dispersion test (SCD) and mitochondrial membrane potential (MMP) were evaluated.
RESULTS
In phase 1, post warm motility rate was higher in PTX exposed group compared to the unexposed group (25.6 ± 8.13 vs. 0.85 ± 2.1) (p > 0.00). Recovery rate, viability and morphology were not significantly different between groups. DNA integrity and MMP were also similar between both groups. In phase 2 although motility increased in PTX group compared to without PTX group (29.30 ± 12.73 vs. 1.90 ± 2.64) (p > 0.00), the viability rate was not different (70.40 ± 12.12 vs. 65.30 ± 11.87). All above mentioned parameters were similar between the two SSC groups.
CONCLUSIONS
Supplementation of testicular spermatozoa with PTX before cryopreservation increases motility and did not have adverse effects on viability, morphology, DNA integrity and MMP. PTX could be used as sperm selection method before single sperm cryopreservation, but PTX could not maintain motile the most of viable testicular sperms.
Topics: Male; Humans; Pentoxifylline; Cryopreservation; Azoospermia; Spermatozoa; Sperm Motility; Semen Preservation; DNA Fragmentation; Testis; Adult; Cell Survival; Membrane Potential, Mitochondrial
PubMed: 38934523
DOI: 10.4081/aiua.2024.12525 -
Neural Regeneration Research Jun 2024In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may...
In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may be an inflammatory trigger, after its release from stress-induced dysfunctional central nervous system mitochondria into peripheral circulation. This evidence supports the potential use of peripheral mitochondrial DNA as a neuroinflammatory biomarker for the diagnosis and treatment of major depressive disorder. Herein, we critically review the neuroinflammation theory in major depressive disorder, providing compelling evidence that mitochondrial DNA release acts as a critical biological substrate, and that it constitutes the neuroinflammatory disease pathway. After its release, mitochondrial DNA can be carried in the exosomes and transported to extracellular spaces in the central nervous system and peripheral circulation. Detectable exosomes render encaged mitochondrial DNA relatively stable. This mitochondrial DNA in peripheral circulation can thus be directly detected in clinical practice. These characteristics illustrate the potential for mitochondrial DNA to serve as an innovative clinical biomarker and molecular treatment target for major depressive disorder. This review also highlights the future potential value of clinical applications combining mitochondrial DNA with a panel of other biomarkers, to improve diagnostic precision in major depressive disorder.
PubMed: 38934398
DOI: 10.4103/NRR.NRR-D-23-01878 -
Intervirology Jun 2024This study aimed to investigate the differences between pregnant women with chronic hepatitis B virus (HBV) infection and intrafamilial infection and those without...
INTRODUCTION
This study aimed to investigate the differences between pregnant women with chronic hepatitis B virus (HBV) infection and intrafamilial infection and those without intrafamilial infection.
METHODS
HBV DNA was extracted from the sera of 16 pregnant women with chronic hepatitis B (CHB) and their family members for gene sequencing and phylogenetic analyses. A total of 74 pregnant women with CHB were followed up from the second trimester to three months postpartum. Viral markers and other laboratory indicators were compared between pregnant women with CHB with and without intrafamilial infection.
RESULTS
The phylogenetic tree showed that HBV lines in the mother-spread pedigree shared a node, whereas there was an unrelated genetic background for HBV lines in individuals without intrafamilial infection. From delivery to three months postpartum, compared with those without intrafamilial infection, pregnant women with intrafamilial infection were related negatively to HBV DNA (β=-0.43, 95% Confidence Interval [CI]: -0.76 to -0.12, p=0.009), HBeAg (β=-195.15, 95% CI: -366.35 to -23.96, p=0.027), and hemoglobin changes (β=-8.09, 95%CI: -15.54 to -0.64, p=0.035) and positively to changes in the levels of alanine aminotransferase (β=73.9, 95%CI:38.92-108.95, p<0.001) and albumin (β=2.73, 95% CI:0.23-5.23, p=0.033).
CONCLUSION
The mother-spread pedigree spread model differs from that of non-intrafamilial infections. Pregnant women with intra-familial HBV infection have less hepatitis flares and liver damage, but their HBV DNA and HBeAg levels rebound faster after delivery, than those without intra-familial infection by the virus.
PubMed: 38934174
DOI: 10.1159/000539994